Seal for bleeder valves



March 24, 1964 N. T. KURFISS 3,126,028

SEAL FOR BLEEDER VALVES Fi lllll ril 13, 1961 INVENTOR. NEAL T. K UUUUss,

allay Y ATTORNEYS United States Patent 3,126,028 SEAL FOR BLEEDER VALVESNeal T. Kurfiss, Middletown, Ohio, assignor to Armco Steel Corporation,Middletown, ()hio, a corporation of Ohio Filed Apr. 13, 1961, Ser. No.102,832 7 Claims. (Cl. 137-329.!)1)

The invention relates to the solution of problems connected with theprovision of bleeder valves for blast furnaces.

As is well known, the top portion of a blast furnace is normallyprovided with a plurality of uptakes which serve as exit means for thefurnace gases. These uptakes are interconnected by a manifold having adowncomer for conducting the furnace gases to a solids separator andthence to a gas washer. The uptakes at their tops are provided withbleeder valves which are either manually or automatically operated forthe purpose of relieving sudden pressure excesses inside the furnace.

The gases from the blast furnace are at an elevated temperature and havelarge quantities of finely divided and highly abrasive solids entrainedin them, so the gases are known as dirty gases. When a bleeder valve isopened, the rush of the abrasive-laden gases past the separated valvetappet and seat cuts and scores these elements, permitting leakage whenthe valve is again closed.

Once a bleeder valve begins to leak, the cutting action proceeds veryquickly because of the channeling of the abrasive-laden gases.

Thus it is necessary frequently to replace the active parts of thebleeder valves, which is a source of great expense and inconvenience,and which cuts down the productive capacity of the furnace since theconventional valve can be repaired or replaced only when the blast istaken ofi the furnace.

It is an object of this invention to provide a valve structure which isnot subject to erosion as described above, or in which erosion isgreatly minimized.

It is an object of the invention to provide a bleeder valve with aneffective seal of the compressive type which will compensate for erosionfor a substantial length of time.

It is an object of the invention to provide a bleeder valve with twoseals whereby the elements forming one seal can remain in closedposition during the repair and replacement of the elements forming theother seal, so that such repair and replacement can be carried onwithout opening the valve and hence without taking the blast off thefurnace.

These and other objects of the invention which will be set forthhereinafter or will be apparent to one skilled in the art upon readingthese specifications are accomplished by that certain construction andarrangement of parts of which an exemplary embodiment will now bedescribed. Reference is made to the accompanying drawings wherein:

FIGURE 1 is a vertical sectional view of a typical bleeder valve towhich the present invention is applied.

FiGURE 2 is a partial enlarged sectional view showing the specificcoaction of the tappet and seat members.

FIG. 3 is a partial sectional view of the elements 8 and 19,illustrating the element 19 as metal.

The particular valve illustrated in FIGURE 1 is of a type in which thetappet moves away from the seat in a downward direction. Types ofbleeder valves in which the tappet moves upwardly away from the seat areequally well known. The skilled worker in the art will understand, inthe light of the teachings herein, how the invention may be applied toeither type; and indeed in FIGURE 2 hereof the right hand element may beconsidered either a part of the tappet or the valve seat part of thebody, while the left hand element may be considered either the seat orthe tappet as the case may be.

In FIGURE 1, the upper end of an uptake is indicated at 1. The bleedervalve includes a bowl-shaped casting surmounted by a cast element 3 ofannular form which serves as the valve seat. A shaft 4 is journaled inbrackets (one of which is shown at 5) on the bowl, and carries a leverarm 6 which is pivoted to a riser portion 7 of a valve tappet 8. Aprojecting end of the shaft 4 carries a lever arm 9, counter-weighted asat 10 and provided at its other end with an operating cable 11. Withinthe bowl 2 there may be guide elements 12 for the movement of the tappet8. As thus far described, the bleeder valve is conventional.

FIGURE 2 shows the coaction of the parts forming the seal of thisinvention. As explained above, this figure shows the two opposite valveparts; and while the lefthand part has been illustrated to comport withthe showing of the tappet 8 in FIGURE 1, with the right hand partcomporting with the valve seat portion 3, these parts may be reversed,so that the member 8 becomes a part of the body of the bleeder valve andthe membelr 3 becomes a part of the tappet.

As illustrated, one of the valve parts, in this instance 8, ischaracterized by a downwardly and inwardly sloping surface 13, abovewhich there is a recess 14. The

other valve part 3 is configured opposite the surface 13 so as topresent a nose 15. A separate and removable metallic member 16 in theform of an annulus, lies on and is held to the member 3 as by bolts 17.This separate metallic member is also configured to present an annularnose 18 lying opposite the recess 14. The recess 14 contains a member 19having a surface 19a coasting with the nose 18 on the member 16. In thepractice of the invention, the member 19 may be made of varioussubstances including metal; but preferably it is made of resilient,heat-resisting substance, and will first be so described.

The shape of the recess 14 may be that shown or may be varied within thelimits of shapes which will hold the resilient member 19, the crosssection of which may also be changed; but the resilient member will havea surface 1% generally coplanar or nearly so, with the surface 13. Therecess may have a slight overhang as at 14a in order to assist inretaining the resilient member.

The resilient member may be made of natural rubber, any of the syntheticrubbers, or of chloroprene such as neoprene. Preferably it is made of amaterial resistant ,to oxidation at somewhat elevated temperatures; andbest results have been obtained through the use of silicone rubber. Asexemplary, a silicone rubber having a dur ometer hardness of 50 plus orminus 5, a tensile strength of 825 pounds per square inch and anelongation of 350% has been found very serviceable.

FIGURE 2 illustrates the positions of the parts upon the first contactof the nose 18 of the separate metallic member 16 with the resilientmember 19. When the valve is fully closed, the member 8 may occupy theposition shown in FIGURE 2 in dotted lines, in which position the nose18 will have deflected the resilient member 19 to a degree as will beevident. In the fully seated position, the nose 15 preferably liesagainst the surface 13; but with the resilient member 19 compressed anddeflected by the nose 18. The exact extent of the deflection is not anecessary limitation on the invention; but in an exemplary embodimentthe deflection is about /4 inch. In testing for the desired heatresistance and resiliency under heat, a suitable material for theresilient member 19 after being tested for twenty-four hours at atemperature of 350 F., with a deflection of 4 inch, showed a permanentset no greater than inch.

The valve of this invention thus forms a gas-tight seal stood that therecess 14 is annular.

between-the metallic nose 18 and the resilient substance 19 whichprevents the escape of the dirty furnace gas. Hence there will be nofiow of gas through the valve when the valve is closed; and the sealwill be effective despite any slight erosion of thenose 18 during therelatively brief intervals when the valve is open.

However, the valve parts of this invention are readily renewed withoutshutting down the furnace or decreasing the furnace top pressure. Itwill be seen in FIGURE 2 that the member 16 may be removed upon removalof the bolts 17. A seal or closure will still be maintained by theengagement of the nose 15 with the surface 13. The member 16 whenremovedor drawn to one side, will completely uncover the recess 14. Theresilient substance 19 may then be removed from the recess and a freshpiece of resilient substance inserted. It will be under- The resilientsubstance 19 is preferably handled in the form of a strip of indefinitelength. 'It may be laid in the recess, and its ends may be cut so as tocome together therein preferably under slight compressive pressure.Further, it is possible to replace the entire member 16, if it isdesired.

While a resilient and compressible member 19 is pre ferred, it ispossible to use other substances (see FIG. 3). A ring of metal may beplaced in the recess 14 (the overhang 14a being eliminated). It is alsopossible to form the annular member 19 from a strip of bendable metal inthe way hereinabove described for the use of a strip of resilientsubstance. Certain of the advantages of the invention may be obtainedeven if the recess 14 and member 19 are omitted and the surface 13 ofmember 8 continued to coact with nose 18 as well as nose 15.

Modifications may be made in the invention without departing from thespirit of it. The invention having been described in an exemplaryembodiment, what is claimed as new and desired to be secured by LettersPatent is:

1. In a bleeder valve construction, a body, relatively movable metallicmembers serving respectively as a valve seat and a valve tappet, one ofsaid members having a substantially conical surface with an annularrecess located intermediate the edges thereof and adapted to contain arenewable valve seat structure, a body of resilient substance Withinsaid annular recess, the other of said members being configured toprovide a first nose positioned for valving coaction with the surface ofsaid first mentioned member, and a second nose coacting with the surfaceof said resilient substance, the said second nose being formed on ametallic body removably mounted upon the valve member having said firstnose, the parts being so related that when said metallic body is removedfrom said valve members, the said annular recess in the first mentionedvalve member will be uncovered for removal and replacement of the bodyof resilient substance therein.

2. The structure claimed in claim 1 wherein the resilient substance is arubbery composition of heat resistant charnular recess except for suchsurface coacting with said second nose.

4. In a bleeder valve construction, a body, relatively movable metallicmembers serving respectively as a valve seat and a valve tappet, one ofsaid members having a substantially conical surface with an annularrecess located intermediate the edges thereof, and containing arenewable valve seat structure, the other of said valve members having apair of noses for effecting valve sealing contacts, one of said nosesbeing formed on a metallic body removably mounted upon said other valvemember, the parts being so related that when said removable member isremoved, the said annular recess will be uncovered for the removal andreplacement of the said renewable valve seat structure.

5. In a bleeder valve construction, a body, relatively movable metallicmembers serving respectively as a valve seat and a valve tappet, one ofsaid members having a substantially conical surface with an annularrecess located intermediate the edges of said conical surface andcontaining a renewable valve seat structure, the other of said membersbeing configured to make valve-closing contact both with said renewablestructure and with said conical surface, that portion of the said otherof said valve members which makes valve-closing contact with saidrenewable structure being located on a metallic body removable from thesaid other valve member and so c0nfigured that, when so removed, it willuncover the said annular recess to permit renewal of the renewable valveseat structure located therein while the said bleeder valve remainsotherwise closed.

6. The structure claimed in claim 5 wherein the said renewable valveseat structure is formed of a distortable substance.

7. In a bleeder valve construction, a body, relatively movable metallicmembers serving respectively as a valve seat and a valve tappet, one ofsaid members having a substantially conical surface, the other of saidmembers having a surface configuration such as to effect valveclosingcontact with said first mentioned member in substantially concentricannular areas, one of said members having an annular recess containing arenewable valve seat structure, and the other of said members having aremovable annular portion, the parts being so related that when saidremovable portion is removed, the said annular recess will be uncoveredfor removal and replacement of the renewable valve seat structure, whilethe valve otherwise remains in closed position.

References Cited in the file of this patent UNITED STATES PATENTS1,665,394 Willoughby Apr. 10, 1928 2,418,200 Smith Apr. 1, 19472,657,897 Folmsbee Nov. 3, 1953 2,949,127 Malina Aug. 16, 1960 2,982,515Rule May 2, 1961 2,995,057 Nenzell Aug. 8, 1961 FOREIGN PATENTS 549,291Canada Nov. 26, 1957

1. IN A BLEEDER VALVE CONSTRUCTION, A BODY, RELATIVELY MOVABLE METALLICMEMBER SERVING RESPECTIVELY AS A VALVE SEAT AND A VALVE TAPPET, ONE OFSAID MEMBERS HAVING A SUBSTANTIALLY CONICAL SURFACE WITH AN ANNULARRECESS LOCATED INTERMEDIATE THE EDGES THEREOF AND ADAPTED TO CONTAIN ARENEWABLE VALVE SEAT STRUCTURE, A BODY OF RESILIENT SUBSTANCE WITHINSAID ANNULAR RECESS, THE OTHER OF SAID MEMBERS BEING CONFIGURED TOPROVIDE A FIRST NOSE POSITIONED FOR VALVING COACTION WITH THE SURFACE OFSAID FIRST MENTIONED MEMBER, AND A SECOND NOSE COACTING WITH THE SURFACEOF SAID RESILIENT SUBSTANCE, THE SAID SECOND NOSE BEING FORMED IN AMETALLIC BODY REMOVABLY MOUNTED UPON THE SAID VALVE MEMBERS, THE SAIDANNULAR RECESS IN THE FIRST MENTIONED VALVE MEMBER WILL BE UNCOVERED FORREMOVAL